A standard wiper comprises a relatively flexible elastomeric blade having a V-section front part that rides on the windshield and a back part formed as a T-section rib that is received in a complementary slot of a somewhat stiffer synthetic-resin backing rail. This rail itself is normally formed along its side edges with oppositely outwardly open grooves in which engage tabs of claws of a metallic yoke assembly. In turn this yoke assembly is formed by a main rigid yoke that itself is carried on the vehicle's wiper arm and whose ends carry short secondary yokes whose ends are formed with the claws that engage in the grooves of the backing rail. Thus the blade and rail can bend to conform to the different curvatures of the windshield it must sweep over.
As described in U.S. Pat. No. 4,156,951 of Sharp the blade is secured to the rail by a removable metallic end clip having a base that lies across and blocks the slot of the backing rail or strip and from which projects a pair of diverging arms that lie on the back face of the backing strip. These arms can be elastically pushed together and are formed as barbs so that they can be inserted through a claw at the end of the wiper. Thus the clip serves the double purpose of preventing the blade from slipping longitudinally out of the backing rail and of holding the rail and blade on the yoke assembly.
In order to hold the blade somewhat offset from the end of the guide rail the above-described Sharp end clip has a short bent-over tab projecting inward from its base into the slot of the rail and engaging the end of the headed rib on the back edge of the blade. This clip therefore holds the blade in place and removal of this clip makes swapping out the blade for a new one fairly easy.
A disadvantage of this assembly is that it is an expensive metallic item in a highly competitive field where costs must be held down wherever possible. The clip can rust in place, and assembly requires the wiper arm to be pulled away from the car so that the clip can be meticulously inserted into the end of the guide rail once the blade is in place.